diff --git a/README.md b/README.md
index 9e0034c..debe0af 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,32 @@
-# DesignPatternsJava9
-This repo consists Gang of Four Design patterns code on Java 9. Each branch in the repository has code of 1 design pattern. Switch repository to try out different design patterns.
+# What is Interpreter Design Pattern
+Interpreter pattern provides a way to evaluate language grammar or expression.
+
+## Diagram
+
+
+
+
+# When to use Interpreter Design Pattern
+* Specialized database query languages such as SQL.
+* Specialized computer languages that are often used to describe communication protocols.
+Voice command based apps.
+
+### Learn Design Patterns with Java by Aseem Jain
+This repository contains working project code used in video Course by Packt Publication with title "Learn Design Patterns with Java " authored by "Aseem Jain".
+
+### Course link:
+https://www.packtpub.com/application-development/learn-design-patterns-java-9-video
+
+###  Profile: http://in.linkedin.com/in/premaseem
+
+### Authors blog on design patterns:
+https://premaseem.wordpress.com/category/computers/design-patterns/
+
+### Software Design pattern community face book page:
+https://www.facebook.com/DesignPatternGuru/
+
+### Note:
+* This code base will work on Java 9 and above versions.
+* `diagrams` folders carry UML diagrams.
+* `pattern` folder has code of primary example.
+* `patternBonus` folder has code of secondary or bonus example.
diff --git a/diagrams/IntrepreterDesignPatternClassDiagram.jpeg b/diagrams/IntrepreterDesignPatternClassDiagram.jpeg
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diff --git a/diagrams/interpreterPattenSequenceDiagram.png b/diagrams/interpreterPattenSequenceDiagram.png
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diff --git a/pattern/src/com/premaseem/Client.java b/pattern/src/com/premaseem/Client.java
index 15f05df..592cbca 100644
--- a/pattern/src/com/premaseem/Client.java
+++ b/pattern/src/com/premaseem/Client.java
@@ -1,13 +1,42 @@
package com.premaseem;
+import java.util.Scanner;
+
/*
@author: Aseem Jain
@title: Design Patterns with Java 9
@link: https://premaseem.wordpress.com/category/computers/design-patterns/
-@copyright: 2018 Packt Publication
*/
public class Client {
public static void main (String[] args) {
- System.out.println("Singleton cook example ");
+ System.out.println("Alexa welcomes you to Artificial intelligence app designed using Interpreter Design pattern :-) ");
+ Scanner scanner1 = new Scanner(System.in);
+ Scanner scanner2 = new Scanner(System.in);
+
+ // User input block
+ String repeatRunFlag = "yes";
+ while (!repeatRunFlag.equalsIgnoreCase("no")) {
+ System.out.println("\n Please ask your question related to voting ...");
+ String question = scanner1.nextLine();
+
+ // get Voting context
+ Context votingContext = new VotingContext();
+
+ // get Rules or grammar around context
+ Expression ruleExpression = votingContext.getRuleExpression();
+
+ // question is interpreted based on context and rules
+ Boolean result = ruleExpression.interpret(question);
+
+ // print Results
+ String voteEligible = result ? "Yes ! can vote :-) ":"No ! cannot vote :-)";
+ System.out.println("Alexa answered: " + voteEligible);
+
+ // Ask from another questions
+ System.out.println("Do you have another questions ? yes / no ");
+ repeatRunFlag = scanner2.next();
+ }
}
}
+
+
diff --git a/pattern/src/com/premaseem/Context.java b/pattern/src/com/premaseem/Context.java
new file mode 100644
index 0000000..627ecac
--- /dev/null
+++ b/pattern/src/com/premaseem/Context.java
@@ -0,0 +1,20 @@
+package com.premaseem;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+interface Context {
+ Expression getRuleExpression ();
+}
+
+class VotingContext implements Context {
+
+ @Override
+ public Expression getRuleExpression () {
+ Expression condition_1 = new TerminalExpression("citizen");
+ Expression condition_2 = new TerminalExpression("18");
+ return new AndExpression(condition_1, condition_2);
+ }
+}
diff --git a/pattern/src/com/premaseem/Expression.java b/pattern/src/com/premaseem/Expression.java
new file mode 100644
index 0000000..35d87a0
--- /dev/null
+++ b/pattern/src/com/premaseem/Expression.java
@@ -0,0 +1,63 @@
+package com.premaseem;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+interface Expression {
+ public boolean interpret (String context);
+}
+
+/**
+ * Terminal Expression is used in other expressions for interpretation
+ */
+class TerminalExpression implements Expression {
+
+ private String data;
+
+ public TerminalExpression(String data){
+ this.data = data;
+ }
+
+ @Override
+ public boolean interpret(String context) {
+ if(context.contains(data)){
+ return true;
+ }
+ return false;
+ }
+}
+
+class AndExpression implements Expression {
+
+ private Expression expr1 = null;
+ private Expression expr2 = null;
+
+ public AndExpression(Expression expr1, Expression expr2) {
+ this.expr1 = expr1;
+ this.expr2 = expr2;
+ }
+
+ @Override
+ public boolean interpret(String context) {
+ return expr1.interpret(context) && expr2.interpret(context);
+ }
+}
+
+class OrExpression implements Expression {
+
+ private Expression expr1 = null;
+ private Expression expr2 = null;
+
+ public OrExpression(Expression expr1, Expression expr2) {
+ this.expr1 = expr1;
+ this.expr2 = expr2;
+ }
+
+ @Override
+ public boolean interpret(String context) {
+ return expr1.interpret(context) || expr2.interpret(context);
+ }
+}
+
diff --git a/patternBonus/src/com/premaseem/Client.java b/patternBonus/src/com/premaseem/Client.java
deleted file mode 100644
index 15f05df..0000000
--- a/patternBonus/src/com/premaseem/Client.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package com.premaseem;
-
-/*
-@author: Aseem Jain
-@title: Design Patterns with Java 9
-@link: https://premaseem.wordpress.com/category/computers/design-patterns/
-@copyright: 2018 Packt Publication
-*/
-public class Client {
- public static void main (String[] args) {
- System.out.println("Singleton cook example ");
- }
-}